Battery Swell Detection

ABSTRACT

A capacitance sensor may be positioned to detect size changes in objects. The sensor may be constructed with to use mutual capacitance or self-capacitance to detect the size changes.

FIELD OF THE DISCLOSURE

This disclosure relates generally to systems and methods for detecting asize. In particular, this disclosure relates to systems and methods forcapacitively sensing changes to size.

BACKGROUND

A change in a size may depict a condition that is useful to know. Forexample, changes in the size of certain device components may indicatethat a part is nearing a failure or indicate the presence of a dangeroussituation. Lithium-ion (Li-ion) batteries are often used in numerousconsumer, military, and aerospace electronic goods such as laptops,cellular phones, satellites, spacecraft, and the like. Li-ion batteriescan present safety hazards because they contain a flammable electrolyte(typically a Li salt) and may need to be kept pressurized. Li-ionbatteries can swell as they start to get old and degrade.

A swollen battery is a potentially dangerous problem in devices thathave a restricted space constraint. Traditionally, laptops, for example,enclosed batteries in rigid plastic or metal cases that confined anyswelling and prevented it from pushing into other parts of the laptop.Typical battery packs may include of a few individual battery cells.Presently, as laptops have become thinner and lighter, individualbattery cells are often encapsulated in a vacuum sealed plastic pouch orbag, and if the battery cell swells the battery pack pushes oncomponents around it. This typically means it pushes on the keyboardand/or the touchpad. Forces from a swollen battery can be quite largeand can cause mechanical damage. Other drawbacks, disadvantages, andinconveniences of present systems and methods also exist.

SUMMARY

In some embodiments, a portable electronic device may include a firstcapacitance sensor, a controller programmed to detect a touch inputand/or a proximity input measured from the first capacitance sensor, asecond capacitance sensor in communication with the controller, and abattery assembly in communication with the second capacitance sensor.The second capacitance sensor is programmed to detect swelling of thebattery assembly.

The first capacitance sensor may be incorporated into a track pad.

The second capacitance sensor may be located between the track pad andthe battery assembly.

The second capacitance sensor may be located between a structuralfeature of the portable electronic device and the battery assembly.

The second capacitance sensor may be connected to an underside of thetrack pad.

The second capacitance sensor may be in physical contact with at leastone cell of the battery assembly.

The second capacitance sensor may be in physical contact with each cellof the battery assembly.

The first capacitance sensor may be a touch screen.

The second capacitance sensor may include a first electrode and acompressible material between the first electrode and the batteryassembly. The capacitance measured with the first electrode may be basedon size of the compressible material.

The second capacitance sensor may include a second electrode. The firstelectrode and the second electrode may be located adjacent a first sideof the compressible material.

The portable electronic device may include a floating coupler. Thefloating coupler may be adjacent a second side of the compressiblematerial that is opposite of the first side of the compressiblematerial.

The portable electronic device may include a second electrode. Thecompressible material may be located between the first insulator and thesecond insulator and the capacitance measured with the first electrodemay be based on a distance between the first electrode and the secondelectrode.

In one embodiment, a portable electronic device may include a controllerprogrammed to detect a touch input and/or a proximity input measuredfrom a track pad of the portable electronic device and detect swellingof an internal object incorporated into the portable electronic devicefrom a capacitance sensor incorporated into the portable electronicdevice.

The capacitance sensor may be located between the track pad and theinternal object.

The capacitance sensor may be located between a structural feature ofthe portable electronic device and the internal object.

The capacitance sensor may be connected to the track pad.

The capacitance sensor may be in physical contact with at least one cellof the internal object.

The capacitance sensor may be in physical contact with each cell of theinternal object.

In one embodiment, a computer-program product for use in a portableelectronic device may include a non-transitory computer-readable mediumstoring instructions executable by a processor to detect a touch inputand/or a proximity input measured from a track pad of the portableelectronic device and detect swelling of a battery assembly incorporatedinto the portable electronic device from a capacitance sensorincorporated into the portable electronic device.

The capacitance sensor may be located between a structural feature ofthe portable electronic device and the battery assembly.

In one embodiment, an apparatus may include an object, a compressiblematerial in mechanical communication with the object, an electrode inmechanical communication with the compressible material, and acontroller programmed to detect a change in capacitance measured withthe electrode when a size of the object changes to change the thicknessof the compressible material.

The compressible material may be 0.1 to 5 millimeters thick.

The compressible material may be a foam, a rubber, a foam rubber, orcombinations thereof.

The electrode may be located on a first insulator.

The apparatus may include a second electrode and a second insulator onwhich the second electrode is located. The compressible material may belocated between the first insulator and the second insulator and thecapacitance measured with the electrode may be based on a distancebetween the first electrode and the second electrode.

The apparatus may include a second electrode located on the firstinsulator. The first insulator may have a bendable region that isconfigured to bend around the object.

The apparatus may include a second electrode. The first electrode andthe second electrode may be located adjacent a first side of thecompressible material.

The apparatus may include a floating coupler. The floating coupler maybe adjacent a second side of the compressible material that is oppositeof the first side of the compressible material.

The capacitance measured with the electrode may be a self-capacitancemeasurement.

The thickness of the compressible material may be configured to shrinkwhen the object expands.

The thickness of the compressible material may be configured to expandwhen the object contracts.

The object may be prone to expanding when a portion of the object outgasses.

The object may be a battery assembly.

The size of the object may be changeable due to temperature.

The size of the object may be prone to change due to humidity.

In one embodiment, an apparatus may include a battery assembly, acompressible material in mechanical communication with the batteryassembly, an electrode in mechanical communication with the compressiblematerial, and a controller programmed to detect a change in capacitancemeasured with the electrode when a size of the battery assembly changesdue to out gassing which causes the compressible material to compress.

The compressible material may be a foam.

The apparatus may include a second electrode and a second insulator onwhich the second electrode is located. The compressible material may belocated between the first insulator and the second insulator and thecapacitance measured with the electrode may be based on a distancebetween the first electrode and the second electrode.

The apparatus may include a second electrode located on the firstinsulator. The first insulator may have a bendable region and may beconfigured to bend around the object.

The apparatus may include a second electrode where the first electrodeand the second electrode are located adjacent a first side of thecompressible material and a floating coupler where the floating coupleris adjacent a second side of the compressible material that is oppositeof the first side of the compressible material.

In one embodiment, a battery assembly may include an electrochemicalstructure, a pouch disposed around the electrochemical structure, afirst electrode incorporated into the battery assembly, a secondelectrode incorporated into the battery assembly, and a controller incommunication with the first and second electrode programed to measure acapacitance between the first electrode and second electrode.

The second electrode may be incorporated into the pouch.

The second electrode may be movable with the pouch.

The first electrode may be affixed to the electrochemical structure.

The first electrode may be incorporated into the pouch.

The first electrode may be a sense electrode disposed within the pouchand the second electrode is a transmit electrode incorporated into thepouch.

The controller may be programmed to send an alert when a capacitancebetween the first electrode and the second electrode reaches apredetermined value.

The battery assembly may include a floating coupler movable with thepouch.

At least one of the first electrode and second electrode may be fixed toa reference surface within the pouch and a distance between the floatingcoupler and at least one of the first electrode and the second electrodeaffects a capacitance between the first electrode and the secondelectrode.

An electrode may be shared with a battery terminal.

The reference surface may be part of the electrochemical structure.

In one embodiment, a computer-program product associated with a batteryassembly may include a non-transitory computer-readable medium storinginstructions executable by a processor to determine a capacitancebetween a first electrode incorporated into the battery assembly and asecond electrode incorporated into the battery assembly.

The instructions may be executable by a processor to send an alert whencapacitance between the first electrode and the second electrode reachesa predetermined value threshold.

At least one of the first electrode and the second electrode may beincorporated into the pouch.

The computer-program product may include a floating coupler disposedwithin the battery assembly and movable with the pouch where a distancebetween at least one of the first electrode and the second electrodeaffects a capacitance between the first electrode and the secondelectrode.

In one embodiment, a battery assembly may include a pouch, a capacitancesensor located at least in part in the pouch, and a controller that isprogrammed to determine a swell size of the pouch based at least in parton the capacitance measurement of the capacitance sensor.

The capacitance sensor may include at least one electrode that ismovable with a portion of the pouch.

The capacitance measurement may be affected by a floating coupler thatis movable with at least a portion of the pouch.

A sense electrode of the capacitance sensor may be disposed within thepouch and a transmit electrode of the capacitance sensor is incorporatedinto the pouch.

The capacitance sensor may be a mutual capacitance sensor with aseparate drive and sense electrode.

The capacitance sensor may be a self-capacitance sensor with anelectrode configured to both drive a voltage and sense the capacitancemeasurement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example of a size detection system in accordance withthe disclosure.

FIG. 2 is a side-view cross-sectional schematic of the portion of thesystem of FIG. 1 along line A-A.

FIG. 3 depicts an example of a size detection system in accordance withthe disclosure.

FIG. 4A is a top-down schematic view of a size sensor in accordance withthe disclosure.

FIG. 4B is a cross-sectional side-view schematic of the size sensor ofFIG. 4A in a folded configuration.

FIG. 5 depicts an example of a multi-cell battery size detection systemin accordance with the disclosure.

FIG. 6 depicts an example of a size detection system in accordance withthe disclosure.

FIG. 7 depicts an example of a size detection system in accordance withthe disclosure.

FIG. 8 depicts an example of a size detection system in accordance withthe disclosure.

FIG. 9 depicts an example of a size detection system in accordance withthe disclosure.

FIG. 10 depicts an example of a size detection system in accordance withthe disclosure.

FIG. 11 depicts an example of a size detection system incorporated intoan electronics device in accordance with the disclosure.

FIG. 12 depicts an example of a size detection system incorporated intoan electronics device in accordance with the disclosure.

FIG. 13 depicts an example of a method for detecting battery swelling inaccordance with the disclosure.

FIG. 14 depicts an example of a method of a battery in accordance withthe disclosure.

FIG. 15 depicts an example of a method of a battery in accordance withthe disclosure.

FIG. 16 depicts an example of a method of detecting a size change inaccordance with the disclosure.

While the disclosure is susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and will be described in detail herein. However,it should be understood that the disclosure is not intended to belimited to the particular forms disclosed. Rather, the intention is tocover all modifications, equivalents and alternatives falling within thespirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

This description provides examples, and is not intended to limit thescope, applicability or configuration of the invention. Rather, theensuing description will provide those skilled in the art with anenabling description for implementing embodiments of the invention.Various changes may be made in the function and arrangement of elements.

Thus, various embodiments may omit, substitute, or add variousprocedures or components as appropriate. For instance, it should beappreciated that the methods may be performed in an order different thanthat described, and that various steps may be added, omitted, orcombined. Also, aspects and elements described with respect to certainembodiments may be combined in various other embodiments. It should alsobe appreciated that the following systems, methods, devices, andsoftware may individually or collectively be components of a largersystem, wherein other procedures may take precedence over or otherwisemodify their application.

For purposes of this disclosure, the term “aligned” generally refers tobeing parallel, substantially parallel, or forming an angle of less than35.0 degrees. For purposes of this disclosure, the term “transverse”generally refers to perpendicular, substantially perpendicular, orforming an angle between 55.0 and 125.0 degrees. For purposes of thisdisclosure, the term “length” generally refers to the longest dimensionof an object. For purposes of this disclosure, the term “width”generally refers to the dimension of an object from side to side and mayrefer to measuring across an object perpendicular to the object'slength.

For purposes of this disclosure, the term “electrode” generally refersto a portion of an electrical conductor intended to be used to make ameasurement, and the terms “route” and “trace” generally refer toportions of an electrical conductor that are not intended to make ameasurement. For purposes of this disclosure in reference to circuits,the term “line” generally refers to the combination of an electrode anda “route” or “trace” portions of the electrical conductor. For purposesof this disclosure, the term “Tx” generally refers to a transmit line,electrode, or portions thereof, and the term “Rx” generally refers to asense line, electrode, or portions thereof.

For the purposes of this disclosure, the term “portable electronicdevice” generally refers to devices that can be transported and includesa battery and electronic components. Examples may include an electricvehicle, a hybrid vehicle, a laptop, a desktop, a mobile phone, anelectronic tablet, a personal digital device, a watch, a gamingcontroller, another device, or combinations thereof. For the purposes ofthis disclosure, the term “mechanical communication” generally refers tobeing in direct physical contact or being in indirect physical contact.As an example, a material that is in direct physical contact with anobject may touch the object. On the other hand, a material that is inindirect physical contact with the object may include being in directphysical contact with an intervening material (or intervening materials)that is in direct physical contact with the object. In this type ofexample, when the material is moved, the material may cause theintervening material to move, which causes the object to move.

For the purposes of this disclosure, the term “floating coupler”generally refers to an electrically conductive material that is notgrounded. In some cases, the floating coupler may be separated fromelectrodes with an electrically insulating material. The capacitancemeasured with the electrodes may be affected based on the distancebetween the floating coupler and the electrodes.

It should be understood that use of the terms “touch pad” and “touchsensor” throughout this document may be used interchangeably with“capacitive touch sensor,” “capacitive sensor,” “capacitive touch andproximity sensor,” “proximity sensor,” “touch and proximity sensor,”“touch panel,” “touchpad,” and “touch screen.”

It should also be understood that, as used herein, the terms “vertical,”“horizontal,” “lateral,” “upper,” “lower,” “left,” “right,” “inner,”“outer,” etc., can refer to relative directions or positions of featuresin the disclosed devices and/or assemblies shown in the Figures. Forexample, “upper” or “uppermost” can refer to a feature positioned closerto the top of a page than another feature. These terms, however, shouldbe construed broadly to include devices and/or assemblies having otherorientations, such as inverted or inclined orientations wheretop/bottom, over/under, above/below, up/down, and left/right can beinterchanged depending on the orientation.

While many of the examples below are depicted with reference to abattery size detection system, the system may be applied to detect sizechanges in any type of objects. For example, the size detection systemmay be used to detect the size changes of solids, gases, liquids,combinations thereof, or complex devices, such as battery assemblies. Inexamples with batteries, the batteries may be located in a laptop,mobile device, an electronic tablet, a vehicle, or another type ofdevice. In some cases, the batteries are lithium batteries. But, inother examples, alkaline batteries or other types of batteries may beused.

FIG. 1 is a top-down schematic view of a size detection system 100 inaccordance with disclosed embodiments. As shown, a disclosed embodimentincludes a sensor 104 that is positioned substantially along the length,width, or other dimension of an object, such as a battery 102 or anothertype of battery. The sensor 104 is constructed with a driven electrode106 and a sensing electrode 108 (see FIG. 2) that run along a thin stripof insulator 116, such as plastic or the like, and where the electrodes106, 108, are separated by a thin (e.g., 0.5 mm) insulating andcompressible material 114 such as foam rubber, or the like. The sensor104 is connected to a drive and sensing circuit 112 via connection 110.

FIG. 2 is a side-view cross-sectional schematic of the portion of thesize detection system 100 of FIG. 1 along line A-A. In thisconfiguration, the sensor 104 is operating in a “mutual capacitance”mode. The compressible material 114 holds the drive electrode 106 andthe sense electrode 108 at a constant or fixed separation indicated as Don FIG. 2.

In use, the sensor 104 strip is preferably attached to a referencesurface, such as the computer wall, or other relatively immobilesupport, adjacent to the object. In some cases, it is preferable to havethe sensor 104 fill the available space between the object and thereference surface. In examples with a battery 102, a pouch or casingaround the electrochemical structure of the battery may fill withventing gases that cause the pouch or casing to expand changing the sizeof the battery. In this example, as the battery's increased size mayfill any open space between the battery 102 and the computer wall. Whenthe space is filled or if there was no open space, the increasing sizeof the battery may increase the pressure on the sensor 104 strip. As thepressure increases, it exerts a pressure on the sensor 104, causing thefoam or other type of compressible material 114 to compress. As thematerial 114 compresses, the drive electrode 106 moves closer to thesense electrode 108 (i.e., the distance D decreases) which increases thecapacitive coupling between the two electrodes. The increased signalthat is coupled onto the sense electrode 108 from the drive electrode106 is measured with a sensing circuit 112. Embodiments of the sensingcircuit 112 may notify a computer, or other processor, which can in turnnotify the user that the battery 102 needs to be replaced soon, or elsephysical damage, or the like, may occur to the computer.

In other examples, this sensor 104 strip could be applied to othercomponents in a computing device, a vehicle, other types of equipment,or combinations thereof. For example, the sensor strip may be applied toa vessel that includes a gas or a liquid. For example, the sensor stripmay be applied to the external surface of hoses, tires, balloons, balls,tanks, pouches, casings, other types of vessels and/or structures thatexpand and contract based on internal pressure, and combinationsthereof. As these types of vessels expand, the compressible material maybe pushed up against a reference surface, such as a surface inequipment, a tire structure, external housing, and so forth. As thecompressible material of the sensor strip is compressed between thereference surface and the vessel, the electrodes in the compressiblematerial may be pushed together indicating the size expansion.

One advantage to using a compressible material is that the force exertedon the sensor can be quantified. For example, the distance between theelectrodes and therefore the capacitance measurement can be correlatedwith a force measurement.

In some cases, the size detection strip may be used to determine that anobject has decreased in size. In this example, as the size decreases,the pressure on the compressible material may lessen causing theelectrodes to move farther away from each other. In this example, thecapacitance measurement between the electrodes may decrease. Thus, insome cases, the sensor strip may be used to determine expansions andcontractions of the object. Such a sensor may assist in capturing cyclicsize changes, vibrations, absolute size changes, relative size changes,other types of size changes and/or patterns, or combinations thereof.

The object may change based on any appropriate factor. For example, theinternal pressure of the object may change based on out gassing, asdescribed with batteries. Other types of objects, other than batteries,may also change size based on out gassing. Out gassing may occur inother types of object when the components of the object experience phasechanges, like through evaporation, or other types of chemical reactions.In other examples, the internal pressure of liquid or gas of the objectmay cause the object to change size. In other examples, size changes dueto humidity and/or temperature may be detectable with the sensor strip.

FIG. 3 is a view of a size detection system 200 in accordance withdisclosed embodiments. This embodiment of system 200 operates the sensor204 in a self-capacitance mode. In this configuration, there is oneelectrode 206 that is driven with a changing voltage, and the parasiticcapacitance can be calculated by measuring the current to drive achanging voltage on the electrode 206. Driving and measuring areaccomplished by a drive and sensing circuit 112. As shown, the sensor204 has an electrode 206 on the one side of the foam or othercompressible material 114, and ground 208 on the other side. As thebattery 102 swells, the foam or compressible material 114 compresses(i.e., distance D gets smaller) which brings the electrode 206 closer tothe ground 208 layer, increasing the parasitic capacitance.

As also shown in FIG. 3, if sensor 204 is mounted adjacent to an object,as a battery 102, such that the electrode 206 side is facing the objectwith a gap in between (indicated as “G” on FIG. 3), the sensor 204 isalso sensitive to the size change as it moves closer to the sensor 204even before it touches the sensor 204. This is a “proximity sensing”mode.

As will be apparent to persons of ordinary skill in the art having thebenefit of this disclosure, any of the herein disclosed embodiments mayuse a sensor (e.g., 104, 204) that is connected to a nearby capacitivetouchpad (not shown) that is part of the computer or otherprocessor-based device. For example, the sensor (e.g., 104, 204) may beconnected into used, or unused, electrode pins on the touch controllerintegrated circuit (IC) for the touchpad. Likewise, the sensor (e.g.,104, 204) may be connected to some other microcontroller that hascapacitive sensing capability. Further, the sensor (e.g., 104, 204) mayhave ground traces around the electrodes (e.g., 106, 206) to shield theelectrodes from environmental changes. Other configurations are alsopossible.

FIG. 4A is a top-down view of a battery size sensor 104 in accordancewith disclosed embodiments, and FIG. 4B is a cross-sectional side-viewof the battery size sensor 104 of FIG. 4A in a folded configuration. Asshown, the sensor 104 has an insulator 116 substrate that may be madefrom a low cost flexible plastic sheet or like. Drive electrode 106 maybe located near one edge, and another sense electrode 108 along theopposite edge as shown. Insulating and compressible material 114 (aportion shown in FIG. 4A) may be placed on top of the insulator 116substrate and the assembly folded in half along bendable region 118 toresult in the FIG. 4B configuration. In use, the FIG. 4B configurationoperates substantially the same as the embodiment disclosed inconnection with FIG. 2.

FIG. 5 is a schematic view of a multi-cell battery size detection system500 in accordance with disclosed embodiments. As shown for a batteryhaving multiple cells 102A, 102B, 102C, 102D the sensors 504A, 504B,504C, 504D may have different sizes, shapes, and electrodeconfigurations that make the sensors 504A, 504B, 504C, 504D moresensitive to some areas than other areas. For example, if a battery packis made with four cells 102A, 102B, 102C, 102D that are mounted in anopen frame all in a row, the sensors 504A, 504B, 504C, 504D may have alarge area over the center of each cell and each large sensor area mightbe connected with a thin trace 510 or other low surface area conductor.As one of ordinary skill in the art would understand having the benefitof this disclosure, the shapes, sizes, locations, connections, and thelike shown in FIG. 5 are merely exemplary and other configurations maybe used. Likewise, mutual capacitance, self-capacitance, proximitysensing, or the like, type sensors may be used in system 500 anddifferent areas might have a different proportion of ground, or driveelectrode, to increase shielding from environmental changes orelectrical noise.

FIG. 6 is a schematic view of a battery size detection system 600 inaccordance with disclosed embodiments. As shown, a first sensor 604A maybe located under battery 102 and a second sensor 604B may be locatedabove the battery 102. If the battery 102 is in a laptop computer, orthe like, the preferred location might be under the palm rest or underthe keyboard, or under the main circuit board. In some embodiments, itis preferable to have a sensor (e.g., 604A, 604B) on both sides of thebattery 102 including between the battery 102 and the outside computercase or housing. As one of ordinary skill in the art would understandhaving the benefit of this disclosure, the shapes, sizes, locations,connections, and the like shown in FIG. 6 are merely exemplary and otherconfigurations may be used. Likewise, mutual capacitance,self-capacitance, proximity sensing, or the like, type sensors may beused in system 600.

FIG. 7 is a schematic partial view of a battery size detection system700 in accordance with disclosed embodiments. As shown, a senseelectrode 708 may be located on an outer surface of the electrochemicalstructure of the battery 102. In some cases, the electrochemicalstructure of the battery includes the metal foils and/or otherstructural components of the battery. In addition, a drive electrode706A may be located on the inside of a pouch 702 wall so that the driveelectrode 706A is positioned above the sense electrode 708.Alternatively, the drive electrode 706B may be located on the outersurface of the pouch 702 as shown. Further, the locations of senseelectrode 708 and drive electrode 706A or 706B may be reversed.Additionally, self-capacitance or proximity sensing configurations mayalso be used.

In some embodiments, a sensing circuit (not shown in FIG. 7) may belocated on a printed circuit board, or the like, within the batterypouch 702, or outside of the pouch 702. In use, the sensing circuitsenses a coupling between the drive electrode 706A, 706B and the senseelectrode 708 when they are in close proximity. As the battery pouch 702fills with gases as the battery 102 degrades, the pouch 702 displacesfrom the battery 102 as indicated schematically on FIG. 7. Thedisplacement also separates the drive electrode 706A, 706B from thesense electrode 708 forming a gap indicated as “G1” (or “G2” forelectrode 706B) in FIG. 7. This gap G1, G2 and reduction in couplingbetween the drive electrode 706A, 706B and the sense electrode 708 ismeasured with the sensing circuit (not shown), and may be communicatedto a battery charging circuit and/or to the computer about the battery102 status, and the computer or computer operator can take correctiveaction such as disconnecting the battery to reduce any further swelling.Other corrective actions may also be taken.

In some cases, the electrode associated with the pouch may be located onthe outside of the pouch, may be located on the inside of the pouch, maybe attached (directly or indirectly) to the inside surface of the pouchso that the electrode moves as the pouch moves, may be incorporated intothe thickness of the pouch, or combinations thereof.

FIG. 8 is a schematic side-view of a battery size detection system 800in accordance with disclosed embodiments. As shown, an electrode 806(e.g., a drive electrode) is located on one side of the battery 102.Another electrode 808 (e.g., a sense electrode) is located on the otherside of the battery 102. A floating coupler 820 wraps around the battery102 to couple the drive 806 and sense 808 electrodes and may be locatedinside a pouch 702 around the battery 102 (or outside pouch 702 aspartially indicated by dashed line 820B). Any change in battery size (orswelling of the battery pouch 702) causes coupler 820 (or if outside820B) to move and the capacitive coupling between electrodes 806, 808changes and may be detected. Such a configuration increases thesensitivity and senses on all sides of the battery regardless of thebattery's location. As will be apparent to those of ordinary skill inthe art having the benefit of this disclosure, the locations ofelectrodes 806, 808 may be switched, a self-capacitance mode using aground connection may be used, or other configurations may also be used.

FIG. 9 depicts an example of a size detection system. In thisillustrated example, an apparatus 900 includes an object 902, a spacer904, a floating coupler 906, compressible material 908, a transmitelectrode 910, a sense electrode 912, and a substrate 914.

The object 902 may be any appropriate type of object that is prone tochanging its size. The size change may occur based, at least in part, onthermal expansion and/or contraction, changes in humidity, chemicalchanges, out gassing, a portion of the object experiencing a phasechange, biological growth, other factors, or combinations thereof. Insome examples, the object 902 may be a battery. In other examples, theobject may be a tire, a hose, a vessel, a rod, a material, an enginecomponent, a gas tank, a liquid tank, a hydrogen cell, another type ofobject, or combinations thereof.

The spacer 904 may fill a gap between other portions of the apparatusand the object 902. In some cases, the spacer 904 may provide electricalinsulation between the object 902 and the floating coupler 906. However,the floating coupler 906 may be made of any appropriate material, whichmay be electrically insulating or electrically conductive. In somealternative examples, no spacer 904 is used between the object 902 andthe floating coupler 906.

The floating coupler 906 may be made of an electrically conductivematerial that is not electrically grounded. Any appropriate electricallyconducting material may be used. For example, a non-exhaustive list ofmaterials that may be used includes copper, nickel, gold, silver,aluminum, steel, iron, brass, bronze, zinc, other metals, electricallyconductive plastics, alloys thereof, mixtures thereof, or combinationsthereof.

The compressible material 908 may separate the floating coupler 906 fromthe electrodes 910, 912. In this example, the floating coupler 906 andthe electrodes 910, 912 are located outside of the compressible material908. However, in alternative examples, at least one of the floatingcoupler 906, the transmit electrode 910, and the sense electrode 912 maybe located within the compressible material 908.

The compressible material 908 may be made of any appropriate material.An example of a non-exhaustive list of materials that may be suitable tobe the compressible material may include foam, rubber, foam rubber, anelastomeric material, other types of materials, or combinations thereof.In some cases, the compressible material is configured to compress inone direction. Yet, in other examples, the compressible material iscapable of compressing and expanding as the size of the objectfluctuates. In some cases, the compressible material is a traditionalspring made from steel or plastic. In some cases, the spring may be usedin non-traditional ways such as but not limited to the inherent springof the existing mechanical structure or substrates. In some cases, suchas the detection of battery swelling, once the battery has beendetermined to swell, the battery is may be replaced for safety andhealth reasons. In this type of application, it is not contemplated thatthe battery will reduce in size allowing the compressible material toexpand. Even if the battery swelling did go down, the battery mayalready be structurally compromised and pose a safety risk. Thus, inthis type of application, the compressible material may not need to beresilient enough to re-expand after compression. However, in other typesof applications, it may be desirable that the compressible material beresilient to expand and contract as the object changes sizes. While thedescription above has identified examples with a battery size detectionsystem that are focused on just determining that a battery has swelled,other applications may include monitoring fluctuating sizes ofbatteries. In some of these examples constructed to monitor fluctuatingsizes, the system may include a compressible material that is capable ofexpanding and contracting as the battery size increases and decreases.

The transmit electrode 910 and the sense electrode 912 may be located onthe substrate 914. In some examples, the transmit electrode 910 providesa voltage which produces a measureable amount capacitance between thetransmit electrode 910 and the sense electrode 912. However, the valueof capacitance may also be affected by the presence of the floatingcoupler 906. In some cases, the closer the floating coupler 906 is fromthe electrodes 910, 912, the greater the effect on the capacitance. Withthe compressible material 908 separating the floating coupler 906 fromthe electrodes 910, 912, changes in the size of the compressiblematerial affect the distance between the floating coupler 906 and theelectrodes 910, 912.

As the object 902 expands, the compressible material 908 is compressed.With the compressible material 908 compressed, the distance between thefloating coupler 906 and the electrode 910, 912 is reduced, which causesan increased change in the capacitance measured with the sense electrode912. The controller (not shown) may determine that when the senseelectrode 912 measures a change in capacitance that the object hasincreased in size. In some cases, an increased change in capacitance mayindicate a size increase in the object 902. In some examples, adecreased change in capacitance may indicated a reduction in size of theobject 902. However, in some alternative embodiments, the electrodes,compressible material, object, floating coupler, or other components ofthe apparatus 900 may be arranged so that a decrease in capacitanceindicates an increase in the object size. Similarly, in somearrangements, an increase in the capacitance measured may indicate thatthe object 902 has reduced in size.

While the example illustrated in FIG. 9 depicts a single transmitelectrode 910 and a single sense electrode 912, multiple transmit and/orsense electrodes may be used. Additionally, in some examples, just asingle electrode is used to measure capacitance. In such an example, thesingle electrode may transmit a voltage and measure a parasiticcapacitance that results from the transmitted voltage.

FIG. 10 depicts an example of an apparatus 1000. The apparatus mayinclude a first sensing stack 1002 and a second sensing stack 1004. Eachof the sensing stacks 1002, 1004 may include a spacer 904, a floatingcoupler 906, a compressible material 908, a transmit electrode 910, asense electrode 912, and a substrate 914 as described in conjunctionwith FIG. 9. However, the first or second sensing stacks may use anyappropriate type of arrangement to detect changes in the sizes of theobject as described in conjunction with FIGS. 1-9. Likewise, othersensing arrangements to use capacitance to detect the size changes inobjects may be used in at least one of the first and second sensingstacks.

In the illustrated example of FIG. 10, the first and second sensingstacks 1002, 1004 are each positioned to detect size changes of the sameobject 902. In some examples, the object 902 may increase in size in anasymmetric manner. For examples where the object 902 is a batteryassembly with multiple cells, one of the multiple cells may swell whilethe other battery cells do not. In this situation, a sensing stack thatis positioned adjacent a cell or a portion of the battery assembly thatis not swelling may not detect the swelling of one of the other cells.In some examples where a multi-cell battery assembly is the object, asensing stack may be positioned to detect size changes for each of thecells. In other examples where the object is not a battery assembly, butmay still be capable of expanding or otherwise changing sizesasymmetrically, multiple sensing stacks may be positioned at differentregions of the object to detect size changes at those regions. In somecases, the multiple sensing stacks may be used to determine relativesize changes or absolute size changes.

FIG. 11 depicts an example of a size detection system 1100 incorporatedinto an electronic device 1102. In this example, the size detectionsystem 1100 includes a first sensing stack 1002 and a second sensingstack 1004 incorporated into a structure of the electronic device 1102.

The electronic device 1102 includes a keyboard surface 1104, a track padassembly 1106 positioned in an opening 1108 defined in the keyboardsurface 1104, and a controller 1110 incorporated into the track padassembly 1106. The track pad assembly 1106 may include a sensor thatincludes at least one electrode for determining a proximity input overthe track pad assembly 1106 or a touch input on to the touch padassembly 1106. The controller 1110 may determine capacitancemeasurements from the electrode to determine the proximity and/or touchinputs of the track pad assembly 1106.

The first sensing stack 1002 and the second sensing stack may bepositioned to detect a size change in a battery assembly 1111 of theelectronic device 1102. The first sensing stack 1002 may be positionedbetween a first post 1112 of the electronic device's structure, and thesecond sensing stack 1004 may be positioned between a second post 1114of the electronic device's structure. Each of the first post 1112 andthe second post 1114 may provide a reference surface against which therespective sensing stacks may push against as portions of a batteryassembly 1111.

In this example, the first sensing stack 1002 and the second sensingstack 1004 are in communication with the controller 1110 of the trackpad assembly 1106. Thus, the circuitry, firmware, and other resources ofthe track pad assembly's controller 1110 may be used to interpret themeasurements from the first sensing stack 1002 and the second sensingstack 1004. In alternative examples, one of the first sensing stack 1002and the second sensing stack 1004 may be in communication with adedicated controller for interpreting their respective measurements.

In the illustrated example of FIG. 11, the region of the batteryassembly 1111 immediately subjacent to the track pad assembly 1106 isvoid of a sensing stack. However, in the embodiment illustrated in FIG.12, a sensing strip 1200 is positioned over the length of the batteryassembly 1111. The sensing strip 1200 may include components andarrangements similar to the arrangements described in conjunction withthe examples from FIGS. 1-10 or another type of capacitance sensingarrangement configured to detect size changes. In this example,connector 1202 connects the sensing strip 1200 to the underside 1204 ofthe track pad assembly 1106. The connector 1202 may provide physicalresistance as the battery assembly 1111 swells causing the compressiblematerial to compress. In some examples, the connector 1202 mayelectrically connect the sensing strip 1200 to the controller 1110 ofthe track pad assembly 1106. In this particular example, the controller1110 may process both the inputs to the track pad assembly 1106 and theinputs from the sensing strip 1200.

FIG. 13 depicts an example of a method 1300 for detecting batteryswelling. This method 1300 may be performed based on the description ofthe devices, module, and principles described in relation to FIGS. 1-12.In this example, the method 1300 includes detecting 1302 a touch inputand/or a proximity input measured from a track pad of the portableelectronic device, and detecting 1304 swelling of a battery assemblyincorporated into the portable electronic device from a capacitancesensor incorporated into the portable electronic device.

FIG. 14 depicts an example of a method 1400 of a battery. This method1400 may be performed based on the description of the devices, module,and principles described in relation to FIGS. 1-12. In this example, themethod 1400 includes determining 1402 a capacitance between a firstelectrode incorporated into a battery assembly and a second electrodeincorporated into the battery assembly.

FIG. 15 depicts an example of a method 1500 of a battery. This method1500 may be performed based on the description of the devices, module,and principles described in relation to FIGS. 1-12. In this example, themethod 1500 includes determining 1502 a capacitance between a firstelectrode incorporated into a battery assembly and a second electrodeincorporated into the battery assembly, and sending 1504 an alert whencapacitance between the first electrode and the second electrode reachesa predetermined value threshold.

FIG. 16 depicts an example of a method 1600 of detecting a size change.This method 1600 may be performed based on the description of thedevices, module, and principles described in relation to FIGS. 1-12. Inthis example, the method 1600 includes detecting 1602 a change incapacitance measured by at least one electrode when a size of the objectchanges.

The electronic device with the touch pad may be a laptop, a desk top, anexternal pad for providing input to a computing device or to the cloudcomputing device, a computing device, a networked device, an electronictablet, a mobile device, a personal digital assistant, a control panel,a gaming device, a flat panel, a display, a television, another type ofdevice, or combination thereof.

It should be noted that the methods, systems and devices discussed aboveare intended merely to be examples. It must be stressed that variousembodiments may omit, substitute, or add various procedures orcomponents as appropriate. For instance, it should be appreciated that,in alternative embodiments, the methods may be performed in an orderdifferent from that described, and that various steps may be added,omitted or combined. Also, features described with respect to certainembodiments may be combined in various other embodiments. Differentaspects and elements of the embodiments may be combined in a similarmanner. Also, it should be emphasized that technology evolves and, thus,many of the elements are exemplary in nature and should not beinterpreted to limit the scope of the invention.

Specific details are given in the description to provide a thoroughunderstanding of the embodiments. However, it will be understood by oneof ordinary skill in the art that the embodiments may be practicedwithout these specific details. For example, well-known circuits,processes, algorithms, structures, and techniques have been shownwithout unnecessary detail in order to avoid obscuring the embodiments.

Also, it is noted that the embodiments may be described as a processwhich is depicted as a flow diagram or block diagram. Although each maydescribe the operations as a sequential process, many of the operationscan be performed in parallel or concurrently. In addition, the order ofthe operations may be rearranged. A process may have additional stepsnot included in the figure.

Having described several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of theinvention. For example, the above elements may merely be a component ofa larger system, wherein other rules may take precedence over orotherwise modify the application of the invention. Also, a number ofsteps may be undertaken before, during, or after the above elements areconsidered. Accordingly, the above description should not be taken aslimiting the scope of the invention.

1. A portable electronic device, comprising: a first capacitance sensor;a controller programmed to detect a touch input and/or a proximity inputmeasured from the first capacitance sensor; a second capacitance sensorin communication with the controller; and a battery assembly beingadjacent to the second capacitance sensor; wherein the secondcapacitance sensor is programmed to detect swelling of the batteryassembly.
 2. The portable electronic device of claim 1, wherein thefirst capacitance sensor is incorporated into a track pad.
 3. Theportable electronic device of claim 2, wherein the second capacitancesensor is located between the track pad and the battery assembly.
 4. Theportable electronic device of claim 2, wherein the second capacitancesensor is located between a structural feature of the portableelectronic device and the battery assembly.
 5. The portable electronicdevice of claim 2, wherein the second capacitance sensor is connected toan underside of the track pad.
 6. The portable electronic device ofclaim 2, wherein the second capacitance sensor is in physical contactwith at least one cell of the battery assembly.
 7. The portableelectronic device of claim 2, wherein the second capacitance sensor isin physical contact with each cell of the battery assembly.
 8. Theportable electronic device of claim 1, wherein the first capacitancesensor is a touch screen.
 9. The portable electronic device of claim 1,wherein the second capacitance sensor includes: a first electrode; and acompressible material between the first electrode and the batteryassembly; wherein the capacitance measured with the first electrode isbased on size of the compressible material.
 10. The portable electronicdevice of claim 9, wherein the second capacitance sensor include: asecond electrode; wherein the first electrode and the second electrodeare located adjacent a first side of the compressible material.
 11. Theportable electronic device of claim 10, further comprising: a floatingcoupler; wherein the floating coupler is adjacent a second side of thecompressible material that is opposite of the first side of thecompressible material.
 12. The portable electronic device of claim 9,further comprising: a second electrode; wherein the compressiblematerial is located between the first insulator and the secondinsulator; wherein the capacitance measured with the first electrode isbased on a distance between the first electrode and the secondelectrode.
 13. A portable electronic device, comprising: a controllerprogrammed to: detect a touch input and/or a proximity input measuredfrom a track pad of the portable electronic device; and detect swellingof an internal object incorporated into the portable electronic devicefrom a capacitance sensor incorporated into the portable electronicdevice.
 14. The portable electronic device of claim 13, wherein thecapacitance sensor is located between the track pad and the internalobject.
 15. The portable electronic device of claim 13, wherein thecapacitance sensor is located between a structural feature of theportable electronic device and the internal object.
 16. The portableelectronic device of claim 13, wherein the capacitance sensor isconnected to the track pad.
 17. The portable electronic device of claim13, wherein the capacitance sensor is in physical contact with at leastone cell of the internal object.
 18. The portable electronic device ofclaim 13, wherein the capacitance sensor is in physical contact witheach cell of the internal object.
 19. A computer-program product for usein a portable electronic device, the computer-program product comprisinga non-transitory computer-readable medium storing instructionsexecutable by a processor to: detect a touch input and/or a proximityinput measured from a track pad of the portable electronic device; anddetect swelling of a battery assembly incorporated into the portableelectronic device from a capacitance sensor incorporated into theportable electronic device.
 20. The computer-program product of claim19, wherein the capacitance sensor is located between a structuralfeature of the portable electronic device and the battery assembly.